1. Field of the Invention
This invention relates to an apparatus for piping system and more specifically to an apparatus for piping system which can be used to prevent vibrations resulting from a flow of fluid within piping or the like, or to disperse a vibration stress generated in a piping system due to earthquakes.
2. Description of the Prior Art
Prior art apparatus for piping system for vibration proofing (sway brace) includes (1) a spring type vibration proof apparatus and (2) a hydraulic vibration proof apparatus (i.e. oil damper). The spring type vibration proof apparatus (1) above has advantages in that the construction thereof is relatively simple, and the characteristic frequency of the entire piping system can be increased readily to avoid the resonance frequency resulting from the distance and the like. However, it sufferred from disadvantages in that the expansion of piping caused by thermal expansion thereof is inconveniently restrained, a limitation involves in large capacity systems in view of the manufacture of springs, and the like. On the other hand, the hydraulic vibration proof apparatus (2) above has advantages in that the resonance frequency may be successfully reduced, the apparatus may follow freely the expansion of piping with little restriction, systems of large capacity may be manufactured relatively freely, and the like. However, the apparatus is poorly responsive to the amplitude of fine vibrations or to the vibrations of high frequency, thus failing to expect the effect, and seals are always subjected to internal stress, and as a result the seals tend to be damaged, and the like.
In Japanese Patent Publication No. 51-47903 of Hitachi Ltd., there is disclosed a technique in which the vibration of pipe is converted into motion of heat resisting particules such as sand through a movable member so that vibrations in a radial and axial direction of pipe may be prevented by friction between said heat-resisting particles. By use of this conventional technique, it is possible to prevent vibrations in multiple directions and to obtain a heat resisting small-size vibration proof apparatus for piping. However, this conventional apparatus is not good in responsiveness with respect to the absorption of vibrations, since the friction between the particles is utilized. Particularly, the absorption factor is poor with respect to fine vibrations, and the resonance phenomenon occurs. Also, in case of great vibrations, a large friction is produced resulting in adverse effects such as shocks.